Procedural perforated aluminum...out of my hands

[Pandekage]

Perhaps it isn't the best idea to choose a crazy skin for our studio project...I need to create this material:

http://www.archdaily.com/132945/town-hall-hotel-rare/

It's sandblasted aluminum with laser-etched patterns.

But I have no idea how to do it. I've attempted regular bumpmaps, which seem to work, but I have no coding experience and cannot figure how to do this procedural pattern. Any hints or steps? And if anyone is feeling generous, a complete material would be very much appreciated for something to show while I learn this.

[Zom-B]

... but I have no coding experience and cannot figure how to do this procedural pattern. Any hints or steps?

No coding needed!
OpenPhotoshop or gimp or even better your favorite vector tool and draw some of your fancy patterns, the more and bigger that map gets, the better.
Now use this map to blend your sandblaster material with a NulllMaterial for alpha output and you end up with holes in the material.

If you wanna get even more fancy and give that holes some depth you need to use your pattern map as a displacement map too, but it needs to have a little wider pattern, by giving them a small outline, since otherwise you simply set the new displaced depth to alpha

have fun!

[Pandekage]

That portion works great! Now it's only the procedural portion that I'm still having trouble with. It's how the detail of the perforations changes as it moves around, from larger squares to smaller ones, spaced apart. I thought there were equations involved in making the texture change like that. Or am I mistaken?

[Zom-B]

Now it's only the procedural portion that I'm still having trouble with. It's how the detail of the perforations changes as it moves around, from larger squares to smaller ones, spaced apart. I thought there were equations involved in making the texture change like that. Or am I mistaken?

I really have no idea how that was handled, I also don't know how perfect your version needs to get, maybe its enough for your shots to get one 3m x3m pattern done and repeat it all over the place. I also would suggest that this question is quite Indigo unspecific and can be asked every where else, maybe you can get a qualified answer in other Forums too!

[Mor4us]

i think you'll have to layer several noises each one blended with this cubic pattern (in different sizes) in photoshop and use it as alpha map in indigo (as Zom-B already mentioned)

you won't be able to copy this pattern 1:1 without a detailed orthogonal view on the facade.

[CTZn]

And ISL approaches will be approximative, different in all cases.

If you copy the image link and paste it in a new tab there will be another image coming up, but it's still not great to get details.

It looks to me like an audio grain sampler used on a 2d noise, ie repetitions with an offset at each iteration, plus a threshold to avoid gaps.

Are the holes made with square shapes ?

[StompinTom]

That portion works great! Now it's only the procedural portion that I'm still having trouble with. It's how the detail of the perforations changes as it moves around, from larger squares to smaller ones, spaced apart. I thought there were equations involved in making the texture change like that. Or am I mistaken?

What I've done for things like this is create the pattern in Rhino with Grasshopper, so you can easily set up a parametric model of just the 2d pattern and adjust it. Then export it out as a black and white image and use as above. It's a bit of a hack and is difficult for large expanses, but it usually works...

[CTZn]

Oh lol, there's a lot of images I just had to scroll down the page...

Sorry about the fuss. Hmm ISL yes... I would have to borrow galinette's pyramid code but then the whole process should be a real challenge with ISL.

I'm not taking this one on me at this point, apologizes

Attached a scene with my early, naive interpretation of the pattern style as an albedo shader. The controls behave crazy anyways.

[Zom-B]

nice start CTZ, I thought that Indigos Box Noise could be a good base to start with..?!

[CTZn]

For the scaled square shapes I would use pyramids, a bigger square being equivalent to hilighting a lower floor of the pyramid (seen from above).

The "grid" used to dispatch the group duplicates is not random, consecutive cells are brighter and brighter and this creates the "sliding" effect.

What bothers me is that overscaled squares in one cell are not cut off but overlaying the next groups, or are overlayed by them... This means hardcoding a long sequence of repeatitive tasks for each cell, off the top of my little head. Meaning that I am even probably wrong.

I'd rather let pandekage do some illustrator works I will consider this again later but I am pessimistic on my ability to resolve it.

[Pandekage]

I'm sorry, but you guys lost me at ISL. With three days I've given up on the procedural aspect, and am now just trying to get a proper perforation. I've tried so many times, to no avail. Attached is a link to the alpha maps I'm using, and an outline of what I'm doing that's not working.

https://docs.google.com/folder/d/0B-O1I ... sp=sharing

1. Create new material in Indigo; in color slot import alpha map
2. Save material somewhere
3. Open Sketchup, create new texture and import saved material (A)
4. Create another sketchup material, change to Blend, load (A) as first material and (none) as second, check Stepblend
5. Render - but of course it doesn't work; the material shows up as an image, but nothing is getting punched out.

[Zom-B]

5. Render - but of course it doesn't work; the material shows up as an image, but nothing is getting punched out.

Exactly ^^
First of all some Skindigo Tutorials that will help you getting familiar with (Sk)Indigo: http://www.youtube.com/playlist?list=PLD14E96A2CD263FE1

the materials setup need to be:

- create in Sketchup a Material A that is the one your building facade is build off
- then create another material inside Skindigo, a blend material
- put your A material into the first slot, and let the second empty to blend with null, enable step blend
- Now load your mask into the blend map, so material A and the NullMaterial get blended based on this map

The last step is the important one... no idea how you came up with the workflow before to work at all ^^

[Pibuz]

...well pandekage..
I dont know if I've well understood your aim...

The firsts shots show some perforated metallic panels with very very low exponent.

What I'd do would be:
1. make a new sketchup material, with a black/white image as the main sketchup texture.
the black/white texture would be the alpha map
2. Open skindigo material dialog window: set the material to be a preset metallic shader, and as clip map choose "SketchUp" from the drop-down list. Specify a very low exponent.
3. Render.

If I have correctly understood, that will do the trick.....

Let me know..

[Pandekage]

Sorry about the late reply, but actually it does work! Thank you Pibuz.

Unfortunately I've hit another snag. I've been using that method for this whole quarter, and it works great - the material is perforated according to the Sketchup texture. But suddenly, out of the blue, the material stops rendering the perforations, instead coming out as a flat metal. I compared the two materials (perforated and not perforated) in the materials preview. The former (perforated) lists it as a blend material with "C_452_perforation_c" (C_452 is the name given to that Sketchup texture) while the latter (broken) lists it as a blend material with "C_default_C" (which I have no idea what it stands for). Any clues as to how I can revert the material to back when it was working? It would suck to have this glitch five days before my project is due..Thanks!